Along with the ever-increasing performance enhancement in electronic devices such as servers or computer mainframes, the demand for better heat-dissipation devices is increasing since a good heat-dissipating device can prevent the operation efficiency or even components of an electronic device from being damaged by the heat emitted during operation. Conventionally, the heat dissipation for servers can be enhanced by the installation of multiple heat-dissipating fans as an array in the vicinity of those heat-emitting components in the servers. Generally, since each of those plural heat-dissipating fans is fixed by the use of a baffle structure composed of a front panel, a rear panel and two brackets, the aforesaid conventional fan fixing method not only is disadvantageous in that: the baffle structures for the whole array of the heat-dissipating fans can occupy a huge space, but also is not favored for its high cost in molding the baffle structures as well as the different materials required for building the baffle structure.
There are already many fan fixing apparatuses that are currently available on the market. One of which is a fan fixing apparatus, disclosed in U.S. Pat. No. 7,2485,490, entitled “Screw-free fan bracket mounting structure”, in that the screw-free fan bracket mounting structure includes a base frame mounted inside the case of a computer and a fan bracket fastened to the base frame for holding a cooling fan, wherein, the fan bracket is configured with a top protruding block, a retaining block and a bottom hook, and the base frame is configured with an upper coupling hole, a retaining hole and a lower coupling hole for receiving the top protruding block, retaining block and bottom hook of the fan bracket respectively so as to enable the distance between the retaining block and bottom hook of the fan bracket to be slightly greater than the distance between the retaining hole and lower coupling hole of the base frame, and thus enabling the fan bracket to be slightly compressed to produce an amount of plastic deformation and secured firmly to the base frame with an elastic force during installation. However, there is neither a clear description, that is stated in the foregoing U.S. patent, relating to how to mount the cooling fan on the screw-free fan bracket mounting structure, nor a description relating to the status of a cooling fan while being mounted on the mounting structure. That is because the object of the aforesaid U.S. patent is to provide a fan bracket mounting structure, which can be easily and rapidly detached and assembled without the use of screws. However, since the fan bracket fastened to a side of the base frame as it is hanging on a wall, the degree stability and support that it can provided to the cooling fan is doubtful. Moreover, since the fan bracket is fasten to the base frame only by the elastic force resulting from the plastic deformation of the fan bracket, such elastic force may become weakening after a period of time due to elastic fatigue so that the fan bracket may not be able to be fixedly secured to the base frame.
Another such fan fixing apparatus, being disclosed in U.S. Pat. No. 6,244,953, is an electronic device fan mounting system, which includes a L-shaped bracket composed of: a front panel, having two wing sheets respectively mounted to the two side thereof; and a bottom panel, being bended symmetrically at two sides thereof for forming two corners. Consequently, a fan unit receiving space can be defined by the enclosure of the front panel, the two wing sheets, the bottom panel and the two corners so as to be used for holding a fan unit. Moreover, each of the wing sheets is fitted with a retention element to be used for interlocking with a corresponding hook formed on a side panel of a housing. The object of the aforesaid U.S. patent is also to provide a fan mounting system for facilitating a fan module to be plugged-in or removed rapidly. Nevertheless, since it is configured with two wing sheets that are protruding outwardly from the two sides of its front panel at positions corresponding to the hooks on the housing, such configuration may require comparatively larger space to install, not to mention that it is impossible to arrange two fan units closely adjacent to each other, i.e. there must be a gap formed between any two neighboring fan units, Thus, there must be a portion of the space inside the housing that is provided for fan units to mount is wasted.
In addition, as disclosed in TW Pat. No. M285896, the fan mounting apparatus comprises: a bracket, fixed to a base; and a fixing element, for fixedly securing a fan to the bracket. The bracket is configured with two side panels, each having a retaining hole formed at a end thereof, whist the fixing element is configured with two elastic fixtures, each having a protrusion formed at a position corresponding to the retaining hole of its corresponding side panel. It is noted that the two elastic fixtures are designed to fix to the top of a fan unit while allowing the two protrusions to inset into the retaining holes of their corresponding side panels. In addition, it is required to have a bottom panel to connected respectively to the two side panels so as to define a fan receiving frame with three surfaces, since without it, the two side panels are certain to swing uncontrollably, causing the fan to slide easily out of the space sandwiched between the two. Thus, the bottom panel is substantially a separated rear baffle. Nevertheless, when it is required to replace a fan unit, it can be a time consuming and wasteful process since the whole assembly of the two side panels and the bottom panel is required to be detached and replaced as a set.